/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.smartloli.kafka.eagle.core.sql.tool;

import java.sql.Date;
import java.text.SimpleDateFormat;
import java.util.Map;
import java.util.TimeZone;
import java.util.concurrent.ConcurrentHashMap;

/**
 * Declare time format.
 *
 * @author smartloli.
 * 
 *         Created by Mar 25, 2016
 */
public class JSqlDateUtils {

	public static final String DEFAULT_DATE_PATTERN = "yyyy-MM-dd";
	public static final String DEFAULT_DATETIME_PATTERN_WITHOUT_MILLISECONDS = "yyyy-MM-dd HH:mm:ss";
	public static final String DEFAULT_DATETIME_PATTERN_WITH_MILLISECONDS = "yyyy-MM-dd HH:mm:ss.SSS";

	static final private Map<String, ThreadLocal<SimpleDateFormat>> threadLocalMap = new ConcurrentHashMap<String, ThreadLocal<SimpleDateFormat>>();

	public static SimpleDateFormat getDateFormat(String datePattern) {
		ThreadLocal<SimpleDateFormat> formatThreadLocal = threadLocalMap.get(datePattern);
		if (formatThreadLocal == null) {
			threadLocalMap.put(datePattern, formatThreadLocal = new ThreadLocal<SimpleDateFormat>());
		}
		SimpleDateFormat format = formatThreadLocal.get();
		if (format == null) {
			format = new SimpleDateFormat(datePattern);
			format.setTimeZone(TimeZone.getTimeZone("GMT"));
			formatThreadLocal.set(format);
		}
		return format;
	}

	public static String formatToDateStr(long millis) {
		return getDateFormat(DEFAULT_DATE_PATTERN).format(new Date(millis));
	}

	public static String formatToTimeStr(long millis) {
		return getDateFormat(DEFAULT_DATETIME_PATTERN_WITH_MILLISECONDS).format(new Date(millis));
	}

	public static String dateToString(Date date) {
		return dateToString(date, DEFAULT_DATETIME_PATTERN_WITHOUT_MILLISECONDS);
	}

	public static String dateToString(Date date, String pattern) {
		return getDateFormat(pattern).format(date);
	}

	public static Date stringToDate(String str) {
		return stringToDate(str, DEFAULT_DATE_PATTERN);
	}

	public static Date stringToDate(String str, String pattern) {
		Date date = null;
		try {
			date = Date.valueOf(str);
		} catch (Exception e) {
			throw new IllegalArgumentException("'" + str + "' is not a valid date of pattern '" + pattern + "'", e);
		}
		return date;
	}

	public static long stringToMillis(String str) {
		if (isAllDigits(str)) {
			return Long.parseLong(str);
		} else if (str.length() == 10) {
			return stringToDate(str, DEFAULT_DATE_PATTERN).getTime();
		} else if (str.length() == 19) {
			return stringToDate(str, DEFAULT_DATETIME_PATTERN_WITHOUT_MILLISECONDS).getTime();
		} else if (str.length() == 23) {
			return stringToDate(str, DEFAULT_DATETIME_PATTERN_WITH_MILLISECONDS).getTime();
		} else {
			throw new IllegalArgumentException("There is no valid date pattern for  : " + str);
		}
	}

	private static boolean isAllDigits(String str) {
		for (int i = 0, n = str.length(); i < n; i++) {
			if (Character.isDigit(str.charAt(i)) == false)
				return false;
		}
		return true;
	}

}